[PATCH v14 08/18] fs: consolidate {nr,free}_cached_objects args in shrink_control

Vladimir Davydov
2013-12-16T12:17:22Z

We are going to make the FS shrinker memcg-aware. To achieve that, we
will have to pass the memcg to scan to the nr_cached_objects and
free_cached_objects VFS methods, which currently take only the NUMA node
to scan. Since the shrink_control structure already holds the node, and
the memcg to scan will be added to it as we introduce memcg-aware
vmscan, let us consolidate the methods' arguments in this structure to
keep things clean.

Thanks to David Chinner for the tip.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
---
fs/super.c | 12 ++++++------
fs/xfs/xfs_super.c | 7 +++----
include/linux/fs.h | 6 ++++--
3 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/fs/super.c b/fs/super.c
index 13c4c92..9084c3d 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -76,7 +76,7 @@ static unsigned long super_cache_scan(struct shrinker *shrink,
return SHRINK_STOP;

if (sb->s_op->nr_cached_objects)
- fs_objects = sb->s_op->nr_cached_objects(sb, sc->nid);
+ fs_objects = sb->s_op->nr_cached_objects(sb, sc);

inodes = list_lru_shrink_count(&sb->s_inode_lru, sc);
dentries = list_lru_shrink_count(&sb->s_dentry_lru, sc);
@@ -96,9 +96,10 @@ static unsigned long super_cache_scan(struct shrinker *shrink,
sc->nr_to_scan = inodes;
freed += prune_icache_sb(sb, sc);

- if (fs_objects)
- freed += sb->s_op->free_cached_objects(sb, fs_objects,
- sc->nid);
+ if (fs_objects) {
+ sc->nr_to_scan = fs_objects;
+ freed += sb->s_op->free_cached_objects(sb, sc);
+ }

drop_super(sb);
return freed;
@@ -116,8 +117,7 @@ static unsigned long super_cache_count(struct shrinker *shrink,
return 0;

if (sb->s_op && sb->s_op->nr_cached_objects)
- total_objects = sb->s_op->nr_cached_objects(sb,
- sc->nid);
+ total_objects = sb->s_op->nr_cached_objects(sb, sc);

total_objects += list_lru_shrink_count(&sb->s_dentry_lru, sc);
total_objects += list_lru_shrink_count(&sb->s_inode_lru, sc);
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index f317488..28d0697 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1524,7 +1524,7 @@ xfs_fs_mount(
static long
xfs_fs_nr_cached_objects(
struct super_block *sb,
- int nid)
+ struct shrink_control *sc)
{
return xfs_reclaim_inodes_count(XFS_M(sb));
}
@@ -1532,10 +1532,9 @@ xfs_fs_nr_cached_objects(
static long
xfs_fs_free_cached_objects(
struct super_block *sb,
- long nr_to_scan,
- int nid)
+ struct shrink_control *sc)
{
- return xfs_reclaim_inodes_nr(XFS_M(sb), nr_to_scan);
+ return xfs_reclaim_inodes_nr(XFS_M(sb), sc->nr_to_scan);
}

static const struct super_operations xfs_super_operations = {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 121f11f..aef5e6b 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1619,8 +1619,10 @@ struct super_operations {
ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
#endif
int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t);
- long (*nr_cached_objects)(struct super_block *, int);
- long (*free_cached_objects)(struct super_block *, long, int);
+ long (*nr_cached_objects)(struct super_block *,
+ struct shrink_control *);
+ long (*free_cached_objects)(struct super_block *,
+ struct shrink_control *);
};

/*
--
1.7.10.4